Valve mechanism for steam-engines.



E. L. BOWEN.

VALVE MEGHANISM FOR STEAM ENGINES.

APPLICATION FILED SEPT. 80, 1908.

923,486. Patented June 1, 1909.

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E. L. BOWEN. VALVE \MEGHANISM FOR STEAM ENGINES.

APPLICATION FILED SEPT. 30, 190B. 923,486, Patented June 1,1909.

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APPLICATION FILED SEPT. 30, 1908. 923,486. I Patented June 1, 1909.

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UNITED STATES PATENT orrro.

EDWARD LEE BOWEN, OF MoCOMB CITY, MISSISSIPPI.

VALVE MECHANISM FOR STEAM-ENGINES.

To all whom it may concern:

Specification of Letters Patent.

Application filed September 30, 1908.

Patented. June 1, 1909.

Serial No. 55,494.

having a reduced lower portion F, extending Be it known that I, EDWARD Lnn BOWEN, in the reduced lower end D of the bushing D.

The main piston valve F is provided with a a citizen of the United States, and a resident of McComb City, in the county of Pike and State of Mississippi, have invented new and useful Improvements in Valve Mechanism for Steam-Engines, of which the following is a full, clear, and exact description.

The invention relates to engines for pumps for fluid pressure brakes, and its object is to provide certain new and useful improvements in valve mechanism for steam engines, whereby the admission and exhaust of the steam are properly controlled, to insure easy and positive working of the brake pump.

The invention consists of novel features and parts and combinations of the same, which will be more fully described hereinafter and then pointed out in the claims.

A practical embodiment of the invention is represented in the accompanying drawings forming a part of this specification, in which similar characters of reference indicate corresponding parts in all the views.

Figure 1 is a sectional side elevation of the improvement, showing the parts in position on the down stroke of the piston in the steam cylinder; Fig. 2 is a similar view of the same and showing the parts on the rip-stroke of the steam cylinder piston Fig. 3 is a sectional plan view of the same on the line 3-3 of Fig. 1; Fig. 4 is a similar view of the same on the line 4 4t of Fig. 2; Fig. 5 is a plan view of the cap plate of the reversing piston valve ;'Fig. 6 is a plan view of the bottom plate of the reversing piston valve, the same being shown in section; Fig. 7 is a side elevation of the bushing; Fig. 8 is a like view of the main piston valve; and Fig. 9 is a similar view of the reversing piston valve.

In the steam cylinder A reciprocates a piston B, connected in the usual manner by its piston rod B with the piston in the air compressing cylinder of the pump. The head 0 of the steam cylinder A is provided with a bushing D having its lower reduced end D closed by an integral bottom D the top of the bushing D being closed by a cap E, bolted or otherwise secured to the head 0.

In the bushing D is mounted to reciprocate a main piston valve F, for controlling the admission and exhaust of the motive agent to and from the cylinder A, as hereinafter more fully described, the said main piston valve F valve F in the bushing D, and the reversing piston valve G is controlled by the piston B in the cylinder A. For this purpose the stem G of the reversing piston valve G is provided with a shoulder G and with a button G adapted to be alternately engaged by a tappet plate H, held on the piston B, so that when the piston B moves downward,

the tappet plate engages the button G and pulls the reversing piston valve G into a lowermost position, as shown in Fig. l, and when the piston B moves into an uppermost position it engages the shoulder G and pushes the reversing piston valve G into an uppermost position, as illustrated in Fig. 2.

Into the lower and upper ends of the steam cylinder A open the ports a and b, of which the port a is partly formed in the cylinder wall and partly in the head C, while the port I) is wholly formed in the cylinder head C. The motive agent supply port 0 is formed partly in the head 0 and partly in the wall of the cylinder A, and this port is connected with the boiler or other suitable source of steam supply. The exhaust port cl is partly formed in the head 0 and partly in the wall of the cylinder A, and the end of the exhaust port (Z within the head C terminates in the forked members 61, d", as plainly indicated in Figs. 1 and 2. The ends of the ports a, l) and c and the terminals of the members (1, (Z terminate in annular recesses a, I), c, d and (1, respectively, surrounding the bushing D and reglstering with rows of annular ports 6, f, 9, 7t and 6, respectively; The ports c, g and 7 open into the interior of the bushing D at the large end thereof, While the ports f and i open into the reduced end D of the said bushing, as will be readily understood by reference to Figs. 1 and 2. The main piston valve F is provided with annular grooves F F, of which the groove F is near the upper end of the main piston valve F and controls the ports e, la, while the lower groove F extends to the lower reduced portion F, and

controls the ports e, g and g, f, respectively. Thus when the several arts are in the position shown in Fig. 1, ive steam from the boiler can pass by way of the port 0 into the annular recess 0 through the ports g into the annular groove F, and from the same by way of the port 6 into the annular recess a and into the port a, to conduct the live motive agent to the lower end of the cylinder A, to force the piston B upward. The motive agent in the upper end of the cylinder A is now exhausted by way of the port Z), recess Z), port 2', annular recess (1 and the end d of the exhaust port d. When the several parts are in the position shown in 2, then live motive agent from the boiler passes by way of the port 0 into the annular recess 0 through the ports {1 into the bushing D, and by way of the annular groove F into and through the ports f to the annular recess Z),

and by way of the port 6 into the upper end of the cylinder A, to force the piston 15 therein in a downward direction.

In order to shift the main piston valve I by the use of live motive agent entering the annular groove F, as above described, the following arrangement is made: The bore F of the main piston valve F is provided near ltS upper end with an annular recess F connected by ports I with the annular groove F so that live motive agent from the groove 1 can pass by way of the ports l into the annular recess The reversing piston valve G is provided with lengthwise-extending grooves G adapted to register with the annular recess and with the upper end of the bushing D, at the time the reversing piston valve G is moved into an uppermost position by the action of the tappet plate II on the shoulder G of the stem G (see Fig. 2). Thus live steam can pass into the upper end of the bushing D, to force the main piston valve F downward into the position show 11 in Fig. 2. In the reversing piston valve G and near the upper end thereof are arranged ports y', adapted to register with the upper end of the bushing D at the time the reversing piston valve G is moved into a lowermost position by the action of the tappet plate II on the button G as shown in Fig. 1. W hen this takes place, the steam in the upper end of the bushing D can escape by way of the port j and the central bore of the reversing piston valve G to the lower end thereof and into the reduced end D of the bushing D, to then pass by way of the port ls, recess d and port d into the exhaust port d. N ow the live steam pressure in the annular groove F forces the main piston valve F upward into the position shown in Fig. 1, owing to the preponderance of pressure against the larger upper area 01" the main piston valve F, in comparison to the reduced end F thereof.

It is understood that the stem portion G extending within the bore of the reversing piston valve G is less in diameter than the bore, to form an annular passage for the escape of the steam from the upper end of the bushing D, as previously explained, the reversing piston valve G being held between top and bottom collars G, G attached to the stem G, the collar G being provided with a cut-out portion Gr (see Fig. 5), to permit some of the steam to pass into the cap E, to

cushion the reversing piston valve G when the latter moves into an uppermost position. The collar G is provided with ports G, adapted to register with an annular recess I) formed in the bottom D of the bushing D, and connected by ports 7c with the exhaust recess d", so that the exhaust steam from the upper end of the bushing D can pass by way of the port 3', the central bore of the reversing piston valve G and ports G into the annular recess D, and by the ports Zr into the exhaust recess (1* and to the exhaust ports d, at the time the piston valve G is in a lowermost position, as shown in Fig. 1.

From the foregoing it will be seen that the reversing piston valve G is moved up and down by the piston B in the main piston valve I and the latter is shifted up and down by the action of the live steam, as before explained, so as to govern the admission of the steam to and from the cylinder A.

Having thus described my invention, I claim as new and desire to secure by Letters Patent:

1. In a valve mechanism a steam cylinder, having a head provided with a bushing hav-' ing a bore with a reduced portion, a main piston valve reciprocating in the said bore and having a reduced portion extending in the reduced portion of the said bore, the said main piston valve controlling the admission and exhaust of the motive agent to and from the said steam cylinder, and a reversing piston valve reciprocating in the said main piston valve and controlling the motive agent to and from the ends of the said bushing to shift the said main piston valve.

2. In a valve mechanism a steam cylinder having a head on one end and provided with an inlet port, ports for connection with the ends of the cylinder and a forked exhaust port, a piston reciprocating in the said cylinder, a bushing fixed in the said head and having ports in register with the said head ports, one end of the bore of the bushing be ing reduced, a main piston valve reciprocating in the said bushing and having a reduced portion extending in the reduced portion of the bushing bore, the said main piston valve having exterior annular rooves adapted to register with the ports in the bushing, the said main piston valve having a central bore provided in its wall with an annular recess connected by ports with one of the said exterior annular grooves, and a reversing piston valve mounted to slide in the bore of the said main piston valve and controlled by the said piston, the said reversing piston valve having an external annular groove in register with the said recess in the said main piston valve.

3. In a valve mechanism a steam cylinder having a head on one end and provided with an inlet port, ports for connection with the ends of the cylinder and a forked exhaust port, a piston reciprocating in the said cylinder, a bushing fixed in the said head and hav ing ports in register with the said head ports, one end of the bore of the bushing being reduced, a main piston valve reciprocating in the said bushing and having a reduced portion extending in the reduced portion of the bushing bore, the said main piston valve having exterior annular grooves adapted to register with the ports in the bushing, the said main piston valve having a central bore provided in its wall with an annular recess connected by ports with one of the said exterior annular grooves, and a reversing valve mounted to slide in the bore of the said main piston valve and controlled by the said piston, the said reversing piston valve having external longitudinal grooves in register with the said recess in the main piston valve, the said reversing piston valve and bushing having exhaust ports for continuously exhausting the steam from either end of the said bushing.

4. In a valve mechanism, a steam cylinder having a hollow head, a piston in the cylinder, a bushing in the head and having a bore with reduced lower portion, a main piston valve having a reduced lower portion and reciprocating in the bore of the bushing, said piston valve controlling the admission and exhaust of the motive agent to and from the cylinder, a hollow reversing piston valve controlling the motive agent to and from the ends of the said bushing, and

means for operating the reversing piston valve from the piston of the cylinder.

5. In a valve mechanism, a cylinder having a hollow head having ports, a piston in the cylinder, a bushing in the cylinder head and having a bore with a reduced lower portion and provided with ports, a main piston valve having a central bore and a reduced portion and reciprocating in the bushing, the said piston valve having annular grooves adapted to register withv the ports of the bushing, and an annular recess in the wall of its bore, said recess being connected with one of the said annular grooves of the valve, and a hollow reversing piston valve in the bore of the main piston and having ports in its sides at the upper end, and means for operating the reversing valve from the piston of the cylinder.

6. In a valve mechanism, a steam cylinder, having a hollow head provided with a hollow cap, a piston in the cylinder, a bushing in the head, a main piston valve having a central bore and reciprocating in the bushing, the said valve controlling the admission and exhaust of steam to and from the cylinder, a hollow reversing piston valve reciprocating in the bore of the main piston valve and having ports in its sides at the upper end, a stem extending through the reversing piston valve and secured therein by caps having ports, the stem being of less diameter than the bore of the valve, and means for operating the reversing valve from the piston of the cylinder.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

EDWARD LEE BOWEN.

Witnesses:

E. J. JoNEs, J. R. NANCE. 

